Just to answer your concern - CJ have been known to scam account holders, but not by charging a fee. A fee will only be charged if there is money in the account balance. When it reaches 0.00, no fee will be charged.

They have been known to charge fees at random however (I experienced this myself). They are also in the habit of deactivating accounts for no apparent reason, regardless of how large the balance in the account is.

My advice - avoid them as the reviews on this website say. Better options are ClickBank and Amazon Affiliates.